Manchester United manager David Moyes' trip to Italy on Sunday was reportedly to watch Cagliari defender Davide Astori as well as Juventus midfielder Claudio Marchisio.
Moyes was spotted Sunday's Serie A game between Cagliari and Juve, leading to speculation that Arturo or Vidal could be on their way to Old Trafford this month.
Reports in Italy last week suggested United are willing to pay up to £20million for Marchisio, who was linked a move to Manchester last year.
However, according to Tuttomercatoweb, Moyes was also at Sunday's league game to watch 27-year-old Astori.
Astori is out of contract at the end of next season and Moyes' reported interest in the centre-back comes following reports that Rio Ferdinand and Nemanja Vidic could be heading for the exit door at Old Trafford at the end of the season.
Vidic is out of contract at the end of the season and has struggled with form and fitness this season, leading to speculation about whether United are prepared to offer him an extension.
The 32-year-old's agent earlier this month said that a move away from the Red Devils could be on the cards, with several clubs showing interest.
"At the moment, I would rule out an extension with Manchester United," Silvano Martina told Radio Crc.
"Vidic, given his contract situation, has several teams looking at him.
"Vidic is a very good player and will have no trouble finding a new club. For the time being we are remaining calm."
Speaking on Friday, Moyes had said of his plans to make new signings this month: "The plans and the decisions won’t change.
"We’ve said that we can go and get targets but it’s difficult to get them at this time.
"I’ve not said we wouldn’t be doing it, but I’ve also said that it’s difficult."